The Bristol ‘tsunami’ – flood or fallacy?

[knocker]

As the current Somerset floods are very much in the news perhaps a quick look back a few years to 1607.

 

30^th January 1607*.

 

The day dawns sunny and bright. You are ploughing a field in your smallholding deep in the Somerset Levels. As the sweat drips down your back, you hear a distant rumbling sound but think nothing of it; the wind has been blowing a gale all night. Suddenly, a shout from a neighbour makes you look up in alarm. At the end of the far field you see a great cloud hugging the ground, light dazzling off the whiteness. At first you are confused: is it fog, or smoke from a fire? But then you realise, it’s water. Within ten seconds, the tumbling, roaring mass has advanced the length of the paddock. You try to run but it’s too late. Knocked off your feet by the force of the wave, your head dips below the surface and you inhale a lungful of salty water…

 

^{*The exact date depends on whether you have a preference for the Julian or Gregorian calendar…}

 

From eyewitness reports, this is what it felt like to be caught up in the most catastrophic flood ever to hit western Britain. Striking in January 1607*, its effects were felt all over the south-west of England, extending over 570 km of coastline from Barnstaple to south Wales and as far inland as Glastonbury (approximately 22km). Contemporary sources put the death toll at over 2,000, though modern estimates have revised this to 500 – 1000¹. The water flow is said to have been so fast “… that no gray-hounde could have escaped by running before them.†But what was the cause?

 

http://betweenarock.co.uk/random-science/the-bristol-tsunami-flood-or-fallacy/

 

A 400 year retrospective.

 

 

The Bristol Channel Floods of January 30, 1607 caused the largest loss of life from any sudden onset natural catastrophe in the United Kingdom during the past 500 years. Between 500 and 2,000people drowned in villages and isolated farms on low-lying coastlines around the Bristol Channeland Severn Estuary. The cause of the flood has itself been controversial, in particular followingclaims in 2002 that the event wasin fact a major tsunami. However, evidence of the timing of thefloods relative to the tides, other weather observations, and the absence of any reports of anearthquake, support the theory that the event was a wind drivenstorm surge superimposed on an

extreme spring tide

 

https://support.rms.com/Publications/1607_Bristol_Flood.pdf

[hillbilly]

As the current Somerset floods are very much in the news perhaps a quick look back a few years to 1607.

 

30^th January 1607*.

 

The day dawns sunny and bright. You are ploughing a field in your smallholding deep in the Somerset Levels. As the sweat drips down your back, you hear a distant rumbling sound but think nothing of it; the wind has been blowing a gale all night. Suddenly, a shout from a neighbour makes you look up in alarm. At the end of the far field you see a great cloud hugging the ground, light dazzling off the whiteness. At first you are confused: is it fog, or smoke from a fire? But then you realise, it’s water. Within ten seconds, the tumbling, roaring mass has advanced the length of the paddock. You try to run but it’s too late. Knocked off your feet by the force of the wave, your head dips below the surface and you inhale a lungful of salty water…

 

^{*The exact date depends on whether you have a preference for the Julian or Gregorian calendar…}

 

From eyewitness reports, this is what it felt like to be caught up in the most catastrophic flood ever to hit western Britain. Striking in January 1607*, its effects were felt all over the south-west of England, extending over 570 km of coastline from Barnstaple to south Wales and as far inland as Glastonbury (approximately 22km). Contemporary sources put the death toll at over 2,000, though modern estimates have revised this to 500 – 1000¹. The water flow is said to have been so fast “… that no gray-hounde could have escaped by running before them.†But what was the cause?

 

http://betweenarock.co.uk/random-science/the-bristol-tsunami-flood-or-fallacy/

 

A 400 year retrospective.

 

 

https://support.rms.com/Publications/1607_Bristol_Flood.pdf

We all know that at some time or other there will be very high tides due to the moon and other planetry effects and it is only a question of time when one of these events is accompanied by very strong winds or stormsurge but there is no question that at times in history that a tsunami will have hit the Bristol channel am sure some geologist could give rough dates when it may have happened,there is a large fault line in the atlantic and if a lump of la palma falls into the atlantic a lot of people in the south will be in trouble!

[Rustynailer]

I speculate that it was a large landslip somewhere in the South-Western approaches, or further out towards the Mid-Atlantic ridge to the South-West of Ireland.

We will probably never know where it came from, until perhaps another.

The argument of storm pushed water does carry some weight however, I agree it is more than possible. Especially as the said storm needn't have even been seen or herd in the UK as powerful as perhaps was out at sea

[4wd]

It's striking how the description rings true from all the Japanese Tsunami videos - in particular you could often see a sort of smoke or mist-like effect as the wave destroyed things as it approached. Also the "tumbling roaring mass" is not a Hollywood tsunami, but much like the videos show as gathered up debris pushes forward like a dam in front of the mass of water.

[AderynCoch]

I wonder how badly the Bristol Channel was hit by the tsunami generated by the 1755 megathrust earthquake, which flattened Lisbon. Cornwall and the south coast of Ireland were hit by a surge generally between 2 & 3 metres high.

 

http://en.wikipedia.org/wiki/Tsunamis_affecting_the_British_Isles#Lisbon_earthquake_.281755.29

[Jackfrost]

I find this subject fascinating. From the amateur research I've carried out, I'd wager the flood being a tsunami rather than a storm surge given the apparently calm, cold weather on the day and the interesting observation of "sparks" at the crest of the wave; classic tsunami behaviour. Then there's the geographical evidence suggesting large rocks had been hurled up the beach at Southerndown. It could have been a storm surge, given the high tides and the fact that flooding was reported in Norfolk soon after, but unless I'm misinformed, a catastrophic storm surge is unlikely to arrive, without warning, on an otherwise uneventful morning. 

 

This documentary is very interesting, perhaps some of you have already seen it. It explores some of the historical and social context as well as the geographical, and it seems to point heavily towards it being a tsunami.

 

http://www.youtube.com/watch?v=tJtEgorCZVc

 

http://en.wikipedia.org/wiki/Bristol_Channel_floods,_1607

[Bobby]

Another far out possibility I've not seen mentioned before is a meteor strike in the Atlantic. Something Tunguska sized would release many megatons of energy into the ocean and could produce a sufficiently sized tsunami. Probably impossible to prove though - unlikely any evidence is left behind so we'll never know if that was the cause.

[Bobby]

Another far out possibility I've not seen mentioned before is a small meteor strike in the Atlantic. Something Tunguska sized would release many megatons of energy into the ocean and could produce a sufficiently sized tsunami. Probably impossible to prove though - unlikely any evidence is left behind so we'll never know if that was the cause.

[radiohead]

For anyone interested in this topic, here's a 100+ report :

 

Tsunamis - assessing the hazard for the UK and Irish coasts (2006)

[knocker]

The Bristol Channel floods of 1607– reconstruction and analys

http://onlinelibrary.wiley.com/doi/10.1256/wea.133.05/pdf

Edited February 5, 2014 by knocker